1. Technical Field
The present invention relates to a method for manufacturing a substrate conjugate, such a substrate conjugate, a method for manufacturing an electro-optical apparatus, and such an electro-optical apparatus.
2. Background Art
In recent years, the following technique has been proposed for manufacturing substrate conjugates prepared by joining two species of substrates that are different from each other. For example, an electro-optical apparatus is manufactured by joining an electro-optical substrate including light-emitting devices such as organic electroluminescent devices (hereinafter referred to as organic EL devices) to a driving circuit substrate including driving devices for driving the light-emitting devices (see Japanese Unexamined Patent Application Publication No. 2002-082633).
In the technique, since the electro-optical substrate and the driving circuit substrate are prepared in different manufacturing steps and the electro-optical apparatus is then manufactured by joining the substrates together, only a small number of steps are necessary to process the driving circuit substrate on which the driving devices, for example, thin-film transistors (hereinafter referred to as TFTs), have been formed or to which the driving devices have been transferred. Hence, this technique is useful in greatly reducing the risk of damage to the driving devices during the manufacturing steps. Since the electro-optical substrate and the driving circuit substrate are prepared in different manufacturing steps as described above, the yield is high. Since the electro-optical substrate and the driving circuit substrate can be prepared in different factories or by companies and then joined to each other in some cases, this technique is advantageous in reducing manufacturing costs. Furthermore, large-screen electro-optical apparatuses can be manufactured with a relatively small capital investment.
In the above technique, the light-emitting devices are electrically connected to the driving devices with an electrically conductive material such as silver paste and a sealing resin is injected between the electro-optical substrate and the driving circuit substrate from the outside. The technique has a problem in that the gap between the substrates cannot be kept substantially constant because the silver paste deforms if one of the substrates is warped. Furthermore, it is difficult to inject the sealing resin between the substrates from the outside when the resin has high gas barrier properties. The technique further has a problem in that the light-emitting devices and the driving devices can be displaced or dislodged due to the residual stress of a polymer contained in the injected resin and/or due to a difference in shrinkage between portions of the resin during a curing step.
The present invention has been made to solve the above problems. It is an object of the present invention to provide a method for manufacturing a substrate conjugate, such a substrate conjugate, a method for manufacturing an electro-optical apparatus, and such an electro-optical apparatus. In the substrate conjugate-manufacturing method, the gap between substrates is kept constant by preventing the substrates from being warped and various devices are prevented from being broken due to residual stress by uniformly injecting a sealing resin between the substrates.